Bridgework 3 Flashcards
What are tx options for missing teeth/severely broken down teeth?
Nothing
RPD
Bridge
Implants
When considering a bridge what must we think about?
Whole mouth - prognosis of pts other teeth - if we end up with large span of edentulous area is a denture more likely better tx option or implants?
What can we guarantee in restorative dentistry?
Every single restoration we place will fail (case of when rather than if - so must consider long term options for that patient and what we can replace it with once failure occurs)
What is the success rates for resin bonded bridges?
5 year - 80%
10 year - 80%
What are the success rates for cantilever bridges?
80% 10 years
What are success rates for fixed fixed bridges?
90% after 10 years
How do we get occlusal information if we are considering prep?
Impressions
mount study casts on semi-adjustable articulator
assess occlusion (incisal class, excursive movements - group or canine), over erupted teeth reducing inter-occlusal space, prafunction)
What do we look at in terms of the occlusion when planning bridgework?
Incisal classification
Movements in excursion - group or canine guidance
Over erupted teeth which reduce the inter occlusal space making it hard to place restoration
parafucntion signs - wear faces, attrition - bridgework may fail
changing occlusion
What are the incisal classifications?
class I - incisal edge of lower incisors lies on or directly beneath cingulum plateau of upper incisors
Class II Div I - incisal edge of lower incisors lies posterior to cingulum plateau of upper incisors and teeth are prolines
Class II Div II - incisal edge of lower incisor lies posterior to cingulum plateau of upper incisors and teeth are retroclined
Class III - incisal edge of lower insures lies anterior to cingulum plateau of upper inciors
What are signs of parafunction?
Wear facets, attrition etc
What must we decide in terms of bridge prep?
Minimal prep?
conventional prep?
How do we asses abutment tooth?
Look clinically at how much tooth tissue ether is
assess pulp - RCT? sensibility testing? assess RCT?
Perio condition - healthy or if perio disease is it inactive and stable?
roots - is root large, multicoated, Abel to withstand forces of missing teeth?
angulation/rotations of tooth?
perio health - if teeth mobile they can’t act as abutment teeth
Why can bridges fail?
Poor moisture control during cementation
Poor OH
Heavy occlusal forces
Unfavourable occlusion
trauma
parafunctional habits
What is risk of bridges in terms of difficulty cleaning?
Risk of caries or PD problems
Why do we have to assess enamel?
We want to bond to to high quality enamel - dentine has inferior chemical bond
When might enamel be hard to bond to ?
Amelogensis imperfecta
Before bridging a tooth what must we do with RCT?
Assess tx - do we need to re-root treat tooth - if we dont and tooth ends up with PA infection the bridge is waste of time
What are the types of bridges?
Adhesive - fixed fixed or cantilever
Conventional - fixed fixed or cantilever or fixed moveable
Hyriid
Spring cantilever bridge
What are the types of bridge poetics?
Sanitary/wash through pontic
Dome pontic
Modified ridge lap
Total ridge lap pontic
Ovate bridge pontic
What is aim of the pontic?
To restore appearance of the missing tooth and give pt additional occlusal surface in aim to restore function and stabilise the occlusion (inc masticatory function)
WHtat 3 things must we consider when making a pontic?
Aesthetics
Cleansability
Strength
What does cleansibility mean in terms of a bridge pontic?
The ability for this area to be clean - pontic must be SMOOTH, HIGHLY POLISHED OR GLAZED SURFACE to snare plaque doesn’t adhere to it inc risk of caries/PD
How should pontic look?
In anterior zone = tooth like
posterior zone = aesthetics less of problem and we can compromise for function rather than aesthetics
What happens to strength of bridge as length of span increases?
As length increases strength of bridge becomes weaker - we need greater strength towithsatnd occlusal forces so may need to make it thicker
What is the occlusal surface of a pontic like?
tooth like and resembles surface its replacing
often narrower to enable cleaning but still needs occlusal contact so its functional and occlusal forces are driven down long axis of abutment teeth
What is a wash through pontic?
has no contact with the edentulous ridge (soft tissues) - floats away from alveolar ridge and pt still ha extra occlusal surface tp bite on
its main aim is FUNCTION rather than AESTEHTICS so good posteriorly!! - consider in lower molar region
very easy to clean
What is advantage of wash through/sanitary pontic?
Easy to clean
for function rather than aesthetics
Where is wash through pontic best used?
Posterior aspect (esp lower molars - not aesthetic!!)
What is a dome shaped pontic?
This is type of pontic that is used in lower incisor, premolar or upper molar region and is where 2/3rds of pontic is tooth like but lower 1/3rd is apically narrowed to aid cleansability in area
When is dome shaped pontic good?
When occlusal 2/3rds of buccal surface is visible - poor if ginvgival 1/3rd is seen
What is the modified ridge lap?
This is where we have the buccal surface of pontic that looks tooth like but lingual surface is cut away - tooth looks good facially but allows is that food can pack lingually which can be cleaned better
problems with food packing on lingual aspect
What is a saddle pontic?
This is pontic with greatest contact of soft tissue - can put pressure on soft tissue and cause temp blanching but its not accessible for food packing so if pt very good OH and motivated then good to presctipe
iF OHI poor the food caking caries, PF
What is the issue with saddle poetics?
Bad if pt has poor OH and motivation as food debris will pack and cause ifnlamamtiona nd caries then perio
What is an ovate pontic?
This is good option for pts with excellent OH and want best aesthetic result- it presses down on gingiva and causes gingiae to mould to pontic so gives appearance of tooth piercing out gum like natural tooth
What might we have to do if doing ovate pontic?
need to prescribe Essex retainer with false tooth which begins to moul gingiva and then pt returns and we are happy with gingival sculpting and we put ovate pontic in - OH MUST BE UNREAL
What types of crowns can be all metal?
Gold
Nickel/cobalt chromium
SS
What are metal ceramic crowns?
Crowns composed of metal and ceramic material (porcelain, zirconia) and are bridge between aesthetics and function (metal inc strength)
What is the problem with all ceramic crowns?
Excellent aesthetics but more prone to fracture du to low strength
What are types of all ceramic crowns?
zirconia
lithium disilicate
When do we opt for all metal crowns?
Lower posterior region - heavy occlusal forces, lower aesthetic demands
When do we opt for metal ceramic crowns?
good for bruxism pts anterior
robust, but aesthetic
What is Lava?
All ceramic crown that is made from zirconia
very strong and rivalling metal work and can withstand occlusal forces - need similar reduction to MCC so no need to be as thick
What is implant retained bridges?
Abutment teeth are implants and can be screw retained or cement retained
What is screw implant retained bridge?
This is where we have access holes on palatal aspect of implant that we put screwdriver down to screw bridge onto implant and then we cover holes with cotton wool or PFTE tape then composite
What is a cement implant retained bridge?
THis is where the implant has abutment on it and fake crown prep and cement using luting agents
Why do we get lab to make us vacuum formed stent?
SO we can check we have adequate reduction during tooth prep
can use to make temp bridge whilst waiting on lab making final bridge
